What was 9/11?
"9/11" is shorthand for four coordinated terrorist attacks carried out by al-Qaeda, an Islamist extremist group, that occurred on the morning of September 11, 2001. The attacks killed 2,977 people.
Why did Al-Qaeda attack the US?
Overall, the attack was to highlight their cause and punish the United States first crimes of religious and other freedoms. Al-Qaeda hoped that, by attacking these symbols of American power, they would promote widespread fear throughout the country and severely weaken the United States’ standing in the world community, ultimately supporting their political and religious goals in the Middle East and Muslim World.